Patent GB-974713-A (GB)
Title: Improvements relating to new substituted 2-phenyl-benztriazole compounds and their use
IPC: C09K15/30
Filed: 1962-06-15
Abstract: The invention comprises 2-(21-hydroxy-31-propenyl-phenyl) benztriazole compounds of the general formula <FORM:0974713/C1/1> , wherein X represents the group <FORM:0974713/C1/2> or <FORM:0974713/C1/3> wherein R1, R2, R3 and R4 represent hydrogen or halogen atoms or alkyl, aralkyl or aryl groups, and the benzene nuclei may be substituted in the 4, 5 or 6 positions (ring A) by halogen atoms or alkyl, alkoxy, carboxyl, carboxylic or sulphonic acid ester or amide, which may be aliphatically, cycloaliphatically, araliphatically or aromatically substituted at the nitrogen atom, or alkylsulphonyl groups and in the 41 or 51 position by alkyl, cycloalkyl, aralkyl, aryl or alkoxy groups or halogen atoms.  The D 2-propenyl compounds may be prepared by the condensation of 2-(21-hydroxylphenyl) benztriazoles with D 2 alkenyl halides of the formula Halogen <FORM:0974713/C1/4> to form 2-(21-alkenyloxyphenyl) benztriazoles of the formula <FORM:0974713/C1/5> and subsequent rearrangement, by heating at 180 DEG  to 220 DEG C. either alone or in an inert solvent or by irradiation with U.V. light. If at least one of R1 to R2 is hydrogen then the D 1-propenyl compound may be obtained by heating the 21 alkenyloxy compound or the D 2-propenyl compound in the presence of a strong base. The condensation is advantageously performed by heating, possibly in the presence of an acid buffering agent, and the 21-alkenyloxy compound formed may at high temperatures be spontaneously rearranged into the D 1 or D 2-propenyl compounds.  Advantageously bromo-or iodo-allyl compounds are used as the D 2-alkenylhalides although allyl chlorides may be used if catalytic amounts of inorganic iodides are present.  Other methods of preparation are (1) the oxidation, e.g. with copper-(II)-salts in an alkaline medium, of (a) 2-amino-21-propenyloxy-1, 11-azobenzene compounds (see Division C4) to give 2-(21-propenyloxyphenyl) benztriazoles and subsequent rearrangement or of (b) 2-amino-21-hydroxy -31- propenyl-1, 11-azobenzene compounds (see Division C4); (2) the reduction, e.g. with zinc dust in an akaline-medium, of (a) 2-nitro-21-propenyloxy-1, 11 azobenzene compounds (see Division C4) to give 2-(21-propenyloxyphenyl) benztriazoles and subsequent rearrangement or of (b) 2-nitro-21-hydroxy -31- propenyl-1, 11-azobenzene compounds (see Division C4); and (3) the saponification of 2-(21-acyloxy -31- propenyl phenyl) benztriazoles, formed, for example, by the oxidation of the corresponding 2-amino-21 acyloxy-1, 11 azobenzene compound or reduction of the corresponding 2-nitro-21 acyloxy-1, 11-azobenzene compound. The products of the invention may be used to protect light sensitive organic materials (see Division C3).  Reference has been directed by the Comptroller to Specification 878,362.ALSO:Polymers are stabilized to U.V. light by incorporation therein of 0.001 to 5% by weight of a 2-(21-hydroxy-31-propenylphenyl) benztriazole of the general formula <FORM:0974713/C3/1> wherein X represents the group <FORM:0974713/C3/2> wherein R1, R2, R3 and R4 represents hydrogen or halogen atoms or alkyl, aralkyl or aryl groups, and the benzene nuclei may be substituted in the 4, 5 or 6 positions (ring A) by hydrogen atoms or alkyl, alkoxy, carboxyl, carboxylic or sulphonic acid ester or amide, which may be aliphatically, cycloaliphatically, araliphatically or aromatically substituted at the nitrogen atom, or alkylsulphonyl groups and in the 41 or 51 positions by alkyl, cycloalkyl, aralkyl, aryl or alkoxy groups or halogen atoms. Specified polymers are polyethylene, polypropylene, polymethyl methacrylate, polyacrylonitrile, polyethylene glycol terephthalates, polycaprolactam and polyether resins.  The stabilize can also be incorporated into the polymer in the form of a 2-(21-alkenyloxyphenyl) benztriazole of the general formula <FORM:0974713/C3/3> which is rearranged on heating the polymer to form the corresponding stabilize.  Hence it is possible to perform the rearrangement during polymerization, e.g. during the polycondensation of nylon or whilst extruding or moulding polyolefines. Plasticizers, antioxidants, heat stabilizers and pigments may also be present in the light stabilized compositions. Polymers may also be protected from U.V. light by coating them with a lacquer comprising the 2-(21-hydroxy-31-propenyl phenyl) benztriazole compounds.  Reference has been directed by the Comptroller to Specification 878,362.ALSO:2 - Nitro - 21 - hydroxy - 31 - a a  - dimethylally -51 - methyl - 1,11 - azobenzene is prepared by coupling diazotized o-nitroaniline with 2-a a -dimethylallyl - 4 - methylphenol.  The 5 - methyl, 5-methoxy and 5-chloro-derivatives of said azobenzene may be obtained in similar manner from the corresponding 4-substituted o-nitro-aniline.  2 - Amino - 21 - hydroxy - 4 - methoxy - 5 - methyl - 31 - allyl - 1,11 - azobenzene is prepared by coupling o-(allyloxy)-aniline with 3-methoxy -4-methylaniline in acetic acid solution and refluxing the azo dyestuff so obtained in dimethyl aniline.  2 - Nitro - 21 - allyloxy - 51 - methyl - 1,11 - azobenzene is obtained by refluxing 2-nitro-21-hydroxy - 51 - methyl - 1,11 - azobenzene with potassium carbonate, sodium iodide, allyl chloride and acetone.  Reference has been directed by the Comptroller to Specification 878,362.